Update system.py
Update system.py

ManjaroLinux support (arch based)
fabtools/fabtools,sociateru/fabtools,ahnjungho/fabtools,bitmonk/fabtools,prologic/fabtools,AMOSoft/fabtools,pombredanne/fabtools,hagai26/fabtools,davidcaste/fabtools,n0n0x/fabtools-python,badele/fabtools,ronnix/fabtools,wagigi/fabtools-python